Philippe II, known as Philip Augustus, King of France, son of Louis VII and Adela, daughter of Theobald II, count of Champagne, was born on the 21st of August 1165. On the 1st of November 1179 he was associated with his father as king by being crowned at Reims, and at once his father's illness threw the responsibility of government on him, the death of Louis on the 19th of September 1180 leaving him sole king.

The boy-king found himself and his kingdom in a difficult and humiliating position. His long strip of royal domain was hemmed in by the Angevin Empire on the west and by the kingdom of Aries on the southeast. King Henry II of England was feudal lord of the greater part of France, practically all west of a line which began at Dieppe and ended at the foot of the Pyrenees more than halfway across to the Mediterranean, while at one point it nearly touched the Rhone. Philip's predecessors had consolidated the Capetian power within these narrow limits, but he himself was overshadowed by the power of his uncles, William, archbishop of Reims; Henry I, count of Champagne; and Theobald V, count of Blois and Chartres. He secured an ally against them, and an addition to the royal domain, by marrying, on the 28th of April 1180, Isabella or Elizabeth, daughter of Baldwin V, count of Hainaut, and of Marguerite, sister of Philip of Alsace, the reigning count of Flanders, who ceded Arras, St. Omer, Aire and Hesdin, and their districts, as Isabella's dowry, a district afterwards called Artois. On the 28th of June 1180 Philip made a treaty with Henry II at Gisors, and his reign thus opened auspiciously. But from 1181 to 1185 he had to struggle against a feudal league of his Champagnard uncles and other great barons, whose most active member was Stephen I, count of Sancerre (1152-1191). Though attacked from both north and south, the king's activity enabled him to compel the count of Sancerre to implore peace in 1181. On the death of Isabel of Vermandois, wife of Count Philip of Flanders, in 1182, Philip claimed Vermandois and seized Chauné and St. Quentin, and forced his father-in-law, Baldwin of Hainaut, to support him by threatening to divorce Queen Isabel. The count of Flanders was obliged to sign the treaty of Boves in July 1185, which gave the king, in addition to the expectation of Artois, his wife's dower, sixty-five castles in Vermandois and the town of Amiens. By 1186 Hugh, Duke of Burgundy, the only member of the coalition not yet subdued, was forced to submit. Then, secure at home, the king turned against Henry II, and by the truce of Châteauroux in June 1187, gained Issoudun and the seigniory of Fréteval in the Vendômois. Though the truce was for two years, Philip assembled an army in 1188 to invade Normandy, demanding Gisors and the conclusion of the marriage which had been arranged between his sister Alice and Richard of England, who had meanwhile deserted his father. But the news came that Saladin had taken Jerusalem and Richard took the cross. Shortly afterwards Philip took advantage of a rising against his quondam friend Richard, who was Duke of Aquitaine, to seize the county of Berry. At a conference at Bonmoulins on the 18th of November Richard again abandoned his father, and after a second conference at La Ferté Bernard, Philip invaded Maine and forced Henry II to conclude the treaty of Azay on the 4th of July 1189, by which the English king did homage and surrendered the territories of Graçy and Issoudun. Henry died two days later. Pledges of mutual good faith and fellowship were renewed between Philip and Richard the Lionheart of England on the 30th of December 1189, and they both prepared to go on the crusade.

Before setting out Philip arranged for the government of France during his absence by his famous testament of 1190, by which he proposed to rule France as far as possible from Palestine. The power of the regents, Adela, the queen-mother, and William, archbishop of Reims, was restricted by a council composed mostly of clerks who had the king's confidence. An annual report on the state of the kingdom was to be sent him. On the way to Palestine the two kings quarrelled. At the siege of Acre Philip fell ill, and on the 22nd of July, nine days after its fall, he announced his intention of returning home. He reached Paris at Christmas 1191, having concluded on his way an alliance with the emperor Henry VI against Richard, despite his pledges not to molest his lands. When Leopold I, Duke of Austria, took Richard prisoner and delivered him to the emperor, Philip did his utmost by offers of money to prolong his captivity, and, allied with the English king's brother John, attacked Richard's domains, but upon Richard's return the Normans rallied enthusiastically to his aid. Philip was defeated at Fréteval on the 3rd of July 1194, but he continued the war, generally with ill success, for the next five years. Again a formidable coalition was formed against him, including Baldwin IX, count of Flanders and Hainaut, Renaud of Dammartin, count of Boulogne, Louis, count of Blois, and Raymond VI, count of Toulouse. In Germany, Otto of Brunswick, afterwards the emperor Otto IV, allied himself with Richard, while Philip was supported by Otto's rival, Philip of Swabia. Richard's death, in April 1199, removed his archenemy, and Richard's successor, John Lackland, concluded the treaty of Le Goulet with Philip on the 22nd of May 1200, ceding to him the county of Evreux, Graçy and Issoudun, and the suzerainty of Berry and Auvergne. John renounced his suzerainty over Brittany and the guardianship of his nephew, Arthur; he engaged not to aid the count of Flanders or Otto IV without Philip's consent, paid him a relief of 20,000 marks, and recognized himself as his vassal for his continental fiefs. Philip's son Louis, afterwards Louis VIII, married Blanche of Castile, John's niece. But in 1202 the war was renewed, John having seized some castles from the family of Lusignan, whose head was the count of La Marche, and taken for his queen a prospective bride, Isabelle Taillefer, from Hugh, son of Hugh IX, count of La Marche. At an interview at Le Goulet on the 25th of March, Philip demanded the cession of Anjou, Poitou and Normandy to his ward, Arthur. John refused; he was summoned to Paris before the royal judges, and failing to appear was sentenced at the end of April 1202 to lose all his fiefs. Brittany, Aquitaine and Anjou were conferred on Arthur. Philip invaded Normandy, took Lyons-a-Forêt and Eu, and, establishing himself in Gournay, besieged Arques. But John, joined by William des Roches and other lords of Maine and Poitou, jealous at the increase of Philip's power, defeated and took Arthur prisoner at Mirebeau. Philip abandoned the siege of Arques in a fit of fury, marched to the Loire, burning everywhere, and then returned to Paris. But John soon alienated the Poitevin barons, and William des Roches signed a treaty with Philip on the 22nd of March 1203. Then Philip continued his great task, the conquest of Normandy, capturing the towns around the fortress of Château-Gaillard which Richard had built to command the valley of the Seine. Pope Innocent III tried to bring about peace, but Philip was obdurate, and after murdering Arthur of Brittany John took refuge in England in December 1203. The fall of Château-Gaillard, after a siege which lasted from September 1203 to April 1204, decided the fate of Normandy. Rouen, bound by ties of trade to England, resisted for forty days; but it surrendered on the 24th of June 1204. The conquest of Maine, Touraine, Anjou and Poitou in 1204 and 1205 was little more than a military promenade, though the castles of Loches and Chinon held out for a year. Philip secured his conquest by lavishing privileges on the convents and towns. He left the great lords, such as William des Roches, in full possession of their feudal power. In 1206 he marched through Brittany and divided it amongst his adherents. A truce for two years was made on the 26th of October 1206 by which John renounced all claims in Normandy, Maine, Brittany, Touraine and Anjou, but it did not last six months. Then Poitou was thoroughly subdued, and another truce was made in 1208, little more than southern Saintonge and Gascony being left in the hands of John. Philip had reduced to a mere remnant the formidable continental empire of the Angevins, which had threatened the existence of the Capetian monarchy.

Philip then undertook to invade England. In the assembly of Soissons on the 8th of April 1213 he made every preparation for carrying out the sentence of deposition pronounced by the pope against John. He had collected 1500 vessels and summoned all his barons when Innocent III, having sufficiently frightened John, sent Pandulph with the terms of submission, which John accepted on the 13th of May.

Disappointed of his hopes of England, Philip turned his arms against Ferdinand, count of Flanders. Ferdinand, son of Sancho I, king of Portugal, owed his county to Philip, who, hoping to find him a docile protégé, had married him to Jeanne, heiress of Flanders, daughter of Count Baldwin IX, who became emperor of the East, using the weak Philip of Namur, her guardian, to accomplish that end. They were married in January 1212. On the morrow of the marriage Louis, afterwards Louis VIII, seized Aire and St. Omer in right of his mother, Isabella, and on this account Ferdinand refused his feudal duty in the English expedition. Moreover, the trade interests of his subjects, who got their raw wool from England, drew him to an alliance with England. Philip's attack brought this about on the 22nd of May 1213. He invaded Flanders and took the chief towns within a week; but he had part of his fleet burned by the English at Damme, and had to burn the rest to save it from falling into their hands. He returned to Paris, and Ferdinand retook most of the towns which had been taken by the king. A war of fire and pillage began, in which Philip and his son Louis burned their way through Flanders, and Ferdinand did the same through Artois.

In 1214 came the great crisis of Philip's life. All the forces against which he had been struggling united to overwhelm him. Paris was to be attacked from Flanders and Guienne at the same time. A league including his rebel vassals, Renaud of Dammartin, count of Boulogne, and Ferdinand, count of Flanders, with the emperor Otto IV and a number of German princes of the Rhine region, had been formed in the northeast, while John of England made one more attempt to recover his heritage at the head of an army of mercenaries aided by the fickle baronage of Poitou. John landed at La Rochelle on the 16th of February 1214, and was at first successful. On the 19th of June he laid siege to La Roche-aux-Moines, the fortress which defended Angers and commanded the Loire valley; but on the approach of a royal army under Prince Louis on the 2nd of July his Poitevin barons refused to risk a pitched battle, and he fled hastily to La Rochelle. The Angevin Empire in France was lost. Meanwhile Philip himself won his greatest victory at the bridge of Bouvines, among the morasses of Flanders. At first taken by surprise, he turned the abortive attack into a complete rout. Renaud and Ferdinand were taken prisoner, and Otto IV fled from the battlefield. The army of the allies was utterly destroyed (July 27, 1214). Nothing shows the progress of the Capetian monarchy more than the enthusiasm and joy of the people of France, as described by William the Breton, over this crowning victory. The battle of Bouvines, a decisive battle for the history of Germany as well as for France and England, sealed the work of Philip Augustus. The expedition of his son Louis to conquer England can hardly be considered as an incident of his reign, though he was careful to safeguard the rights of the French Crown. More important was the Albigensian crusade, in which he allowed Louis to take part, though he himself, preoccupied with the king of England, had refused time after time to do anything. He treated Simon de Montfort as if he were a royal bailli; but it was not in virtue of any deep-laid scheme of his that in the end Amaury de Montfort, Simon's son, resigned himself to leave his lands to the Crown of France, and gave the Crown a power it had never before possessed in Languedoc.

Even more than by his conquests Philip II marks an epoch in French history by his work as an organizer and statesman. He surrounded himself with clerks and legists of more or less humble origin, who gave him counsel and acted as his agents. His baillis, who at first rather resembled the itinerant justices of Henry II of England, were sent into the royal domain to supervise the conduct of the prévôts and hear complaints, while in the newly acquired lands in the south local feudal magnates were given similar powers with the title of sénéchal. Feudal service was more and more compounded for by a money payment, while additional taxes were raised, all going to pay the mercenaries with whom he fought Richard I and John. The extension of the system of sauvegarde, by which abbeys, towns or lay vassals put themselves under the special protection of the king, and that of pariage, by which the possessor surrendered half the interest in his estate to the king in return for protection or some further grant, increased the royal power. The small barons were completely reduced to submission, whilst the greater feudatories could often appoint a castellan to their own castles only after he had taken an oath to the king. Philip supported the clergy against the feudal lords, and in many cases against the burgesses of the towns, but rigidly exacted from them the performance of their secular duties, ironically promising to aid the clergy of Reims, who had failed to do so, "with his prayers only" against the violence of the lords of Rethel and Roucy. He clung to his right of regale, or enjoyment of the revenues of bishoprics during their vacancy, though it was at times commuted for a fixed payment. The attempt to raise a tithe for the crusade in 1189 failed, however, before a general resistance owing to an unfair assessment.

It has been said with some justice that Philip II was the first king of France to take the bourgeoisie into partnership. He favored the great merchants, granting them trade privileges and monopolies. The Jews he protected and plundered by turns, after the fashion of medieval kings. Amongst the subject towns administered by prévôts a great extension of the "custom of Lorris" took place during his reign. But it is as the ally and protector of the communes that he takes his almost unique place in French history. Before him they were resisted and often crushed; after him they were exploited, oppressed, and finally destroyed. In the case of Senlis he extended the jurisdiction of the commune to all crimes committed in the district. It is true that he suppressed some communes in the newly conquered fiefs, such as Normandy, where John had been prodigal of privileges, but he erected new communes in his own private domain, quite contrary to the custom of other kings. He seems to have regarded them as a kind of garrison against feudal unruliness, while the rents they furnished increased his financial resources. He created no new types of commune, however, except Peronne, which received a maximum of political independence, the twenty-four electors, who named the jurés and other officers, being elected by the corps de métiers.

The newly organized powers of the Crown were in evidence everywhere, interfering in the family affairs of the great feudatories and taking advantage of minorities, such as that of Theobald IV of Champagne. The great feudatories accepted his legislation on dower in 1214 and 1219 and the établissement of 1209 making co-heirs of fiefs hold direct from the king and not from one of their number. The Tournois was substituted for the Angevin money in Normandy after 1204. The army which safeguarded this active monarchy consisted chiefly of mercenaries. The old feudal ost was but rarely convoked. The communes, though they appear as taking part in the battle of Bouvines, compounded for their service by a money payment as early as 1194.

Philip's policy of building up a strong monarchy was pursued with a steadiness of aim which excluded both enthusiasm and scruple. But he seems to have prided himself on a certain humanity, or even generosity of temper, which led him to avoid putting his enemies to death, though he did not scruple to condemn Renaud of Dammartin to the most inhuman of imprisonments. He was impulsive and could display extraordinary activity at times, but he possessed also a certain coldness and caution. He shrank from no trickery in carrying out his ends, and had no room for pity. He could not even trust his own son with any power, and was brutal in his relations with his queen, Ingeborg. He is described by Paiën Gâtineau as "a well-knit, handsome man, bald (from his illness at Acre), of agreeable face and ruddy complexion, loving good cheer, wine and women. Generous to his friends, he was miserly to those who displeased him; very skilled in the art of the engineer, catholic in his faith, far-seeing, obstinate in his resolution. His judgment was sound and quick. He was also quick in his anger, but easily appeased." As the result of his steadiness of aim and patient sagacity, at the end of his reign the Crown was victorious over the feudal nobility and the royal domain extended to the frontiers along with royal authority. Artois, the Amienois, Valois, Vermandois, the greater part of the Beauvaisis, Normandy, Maine, Anjou, Touraine, and an important part of Poitou and Saintonge, were added to the domain during his reign. The number of prévôtés was increased from thirty-eight to ninety-four, and the royal revenue increased from 19,000 livres a month to 1200 livres a day.

Philip Augustus died on the 14th of July 1223. He was thrice married. His first wife, Isabella, by whom he had one son, Louis, died in 1189 or 1190. After her death he married Ingibörg or Ingeborg, daughter of Valdemar I of Denmark. This unlucky marriage was negotiated, it is said, chiefly to acquire the old claims of Denmark over England, to be used as a weapon against Richard I. However that may be, he soon repudiated this Danish princess, for whom he seems to have conceived an unconquerable aversion on the very morrow of his marriage to her, and in 1196, in defiance of the pope, who had refused to nullify his union with Ingeborg, married Agnes, daughter of Bertold IV, Duke of Meran. This led to his excommunication and brought the interdict upon France, and did more to weaken him than any other act of his. In 1200 he was forced to put away Agnes and to recognize Ingeborg as his lawful wife, but he kept her in prison until 1213. By Agnes (d. 1201) he had a son Philip, called "Hurepel", count of Clermont, and a daughter Mary, who married Philip, count of Namur (d. 1213), and then Henry II, duke of Brabant. Ingeborg lived until 1236.